<style type="text/css">
    table {
        border-collapse: collapse;
    }
    #one td {
        border: 1px solid #ff0000; 
    }
</style>

<table>
    <tr id="one">
        <td></td>
        <td></td>
    </tr>
    <tr id="two">
        <td></td>
        <td></td>
    </tr>
</table>

With border-collapse set to collapse, the solution would be to use an inset border for all the cells, and a solid border for the cell that the mouse hovers over. Here's the suggested CSS in action: http://jsfiddle.net/QmHGG/

The following is the CSS that was applied to the table:

table, tr, td {
    border: 1px inset black;
    border-collapse: collapse;
    border-spacing: 0;
}

td:hover {
    border: 1px solid red;
}

I would acheive this by using adjacent selectors, like so:

table {
    border: 1px solid #000;
}

tr {
    border-top: 1px solid #000;
}

tr + tr {
    border-top: 1px solid red;
}

td {
    border-left: 1px solid #000;
}

td + td {
    border-left: 1px solid red;
}

It's a little bit repetitive, but it acheives the effect you're after by setting the top and left borders of the first row and column respectively, then overwriting the 'internal' rows and cells with red.

This won't of course work in IE6 as it doesn't understand the adjacent selectors.

http://jsfiddle.net/JaF5h/36/